title: N-Nitroso-N-methylurea elicits mammary cancer in resistant and sensitive rat strains.
abstract: A single intravenous (i.v.) injection of the water-soluble mammary carcinogen N-nitroso-N-methylurea (NMU; 35 mg/kg of body weight) elicited cancer of the breast in young female rats of two strains in the following incidence: Long-Evans strain, 4%; Sprague-Dawley strain, 70%. In sisters of these rats, a set of 5 i.v. injections of NMU (35 mg/kg at biweekly intervals) evoked mammary carcinoma as follows: Long-Evans strain, 76%; Sprague-Dawley strain, 100%. In its effectiveness in evoking mammary cancer in Sprague-Dawley rats, the lipid-soluble mammary carcinogen 7,8,12-trimethylbenz[a]anthracene exceeded NMU in rapidity of development of cancer and in tumor yield.
mesh_terms: D015127:9,10-Dimethyl-1,2-benzanthracene / Q000031:analogs & derivatives; D000818:Animals; D004351:Drug Resistance; D005260:Female; D008325:Mammary Neoplasms, Experimental / Q000139:chemically induced* / Q000473:pathology; D008770:Methylnitrosourea; D009607:Nitrosourea Compounds; D051381:Rats; D013045:Species Specificity
chemical_list: D009607:Nitrosourea Compounds; C029538:7,8,12-trimethylbenz(a)anthracene; D015127:9,10-Dimethyl-1,2-benzanthracene; D008770:Methylnitrosourea